[1] ES, DNA NR RG 48, Department of Interior, Lands and Railroad Divisions, Union Pacific Railroad Company, Package 239. Lincoln's endorsement is written on the back of a letter from Thomas C. Durant, vice-president of the Union Pacific, November 3, 1864: ``I have the honor to ask your approval of the permanent location of the first one hundred miles of the Union Pacific RailRoad as indicated by the map forwarded to the Department of the Interior on the 24th. ulto.''